Heat exchange apparatus



Jan. 16, 1934.

J. A. POTTER HEAT EXCHANGE APPARATUS Filed April 17, 1935 2 Sheets-Sheet l INVENTOR ATTORNEY JOHN A. POTTER.

Jan. 16, 1934. J. A. POTTER 1,943,456

HEAT EXCHANGE APPARATUS Filed April 17, 1933 2 Sheets-Sheet 2 FIG. 5.

INVENTOR JOHN A. POTTER ATTORNEY Patented Jan. 16, 1 934 a UNITED STATES PATET OFFECE HEAT EXCHANGE APPARATUS Pennsylvania Application April 17, 1933. Serial No. 666,579

9 Claims. (01. 257-236) My invention relates to generators of the type wherein a medium contained in a receptacle is vaporized by heat derived from a second medium of higher temperature and passing through tubes immersed in the first medium, and it has for its object to provide improved means permitting of the tubes bowing in operation to facilitate the disengagement of scale.

In accordance with my invention, I provide a tube bundle assembly, including tubes and boxes connected to the ends thereof, a shell, and end covers for the shell having abutment relation with respect to the boxes, whereby the shell is effective in tension to resist relative spreading movement of the boxes incident to expansion of the tubes with the result that the tubes bow to accommodate the expansion. As the extent of bowing depends upon temperature conditions and as such conditions are variable, it will be apparent that, in operation, the bowing move ment may be relied upon for the purpose stated. My invention may be embodied with the tubes arranged in various ways: one or more bundles maybe arranged as a single nest with the shell and the end covers acting compressively thereon, or the nests may abut in end-to-end relation with the covers acting on the outermost ends thereof;

In the drawings- Fig. l is a longitudinal sectional view of tubular heat exchange apparatus embodying my improvement;

Fig. 2 is an end elevation viewed from the left of Fig. 1 with the left-hand cover removed;

Fig. 3 is a sectional view of a box taken along the line III--III of Fig. 2;

Fig. 4 is a detail view of one of the supports for holding the associated tubes in a bowed con dition; and

Fig. 5 is a longitudinal sectional view of apparatus having tube nests arranged in end-to-end abutting relation and embodying my invention.

In Fig. 1, the horizontal shell has end covers 11 and 12. Medium to be vaporized is supplied interiorly of the shell in any suitable manner, for example, through the inlet 9 and heating medium is supplied through connection 13. The shell is also provided with a blow-01f outlet 14 at the bottom and one or more vapor outlets 15 at the top.

A tube nest aggregate is shown at 16 and it ineludes one or more tube bundles 17, each tube bundle including tubes 18 and boxes 19 and 20.

The end covers 11 and 12 cooperate with the boxes 19 and 20 to prevent relative spreading of the latter in consequence of tube expansion, the expansion stress being resisted by the shell acting in tension. As the end covers function as beams in transmitting stress, they should be constructed with this purpose in view. Accordingly, each cover is provided with one or more vertical ribs 21 to give vertical stiffness and horizontal upper and lower ribs or webs 22 and 23 are arranged between the covers and the boxes 19 and 20, the latter preferably having horizontal upper and lower pads 24 and 25 for abutment with the webs or ribs 22 and 23, respectively.

The tubes 18 are preferably bowed and the bundle is provided with means for maintaining the tubes thereof in bowed condition before assembly of the bundle in the shell. To this end, I show the box 19 having a lower series of horizontal beams, preferably angles 26, having slidable connections 27 withthe other box 20 and the box 20 having an upper series of horizontal beams 28 connected thereto and having slidable connections 29 with the box 19. Support plates 31 (Fig. 4) have openings 32 for tubes and upper and lower openings 3S'and 34 for the upper and lower beams 28 and 26, the openings being so disposed that, with tubes in the openings 32 and'tops of the openings 33 and 34 engaging tops of the upper and lower angles, the tubes will be in bowed condition, as shown in Fig. 1. 'The openings 33 and 34 areelongated vertically to permit of the tubes bowing up-' wardly and carrying the associated plate 31 upwardly relatively to the upper and lower angle beams 28 and 26.

As shown in Fig. 1, the box 20 is at a slightly higher elevation than the box 19, the box 20 being supplied with heating medium, for example, steam, from the element 36 and the steam then passing from the box 20 to and through the tubes 1'7 to the box 19. The element 36 functions in a well known manner as a superheater, for it is arranged above the normal water level in the shell and steam entering the inlet 13 passes therethrough before reaching the evaporator tubes 1'7; and, therefore, heat given up from steam passing through the element 36 to saturated vapor emitted from the Water serves to superheat such vapor. Steam gives up heat to the vaporizable medium in the shell and is condensed. Therefore, by having the tubes 17 inclined downwardly from the upper right hand box 20 to the lower left hand box 19, drainage toward the latter is assured, whereby efiective flow of heating medium is maintained. The lower box 19 is provided with a condensate outlet 37.

The slidable connections 27 and 29 of the angles 26 and 28 with respect to the boxes 20 and 19, respectively, provide for movement of the tube plates associated with the boxes when apparatus is being assembled.

The tube bundle, including the tubes 17, the boxes 19 and 20, and associated structure, is supported from the shell in any suitable man ner. For example, I show brackets 38 and 39 on the shell covers on which rest pads 24 and 25 of the bundle.

In Fig. 5, I show a relatively long shell 40 having end covers 41 and 42 and enclosing tube bundles 43 and 44 arranged in tandem. Adjacent boxes 45 and 46 of the bundles abut and the outermost boxes 4'7 and 48 of the bundles abut the covers 41 and 12, whereby, as before, the shell is effective in tension to oppose relative spreading of the boxes due to tube expansion, expansion being accommodated by bowing of the tubes.

While I have shown my invention in two forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of Various other changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. In apparatus of the character described, a tube bundle including tubes and boxes connected to the ends thereof and means for resisting relative spreading of the boxes due to tube expansion including a shell, encompassing the bundle and having end covers disposed in abutting relation with respect to the boxes.

2. In apparatus of the character described, a tube bundle including tubes and boxes connected to the ends thereof, a shell encompassing the tubes and having end covers, and compression spacing means arranged between the cover interiors and the boxes to prevent relative separating movement of the latter to cause the tubes to bow incident to expansion thereof.

3. The combination as claimed in claim 2 with means for holding the tubes in an initially bowed condition and providing for bowing in excess thereof.

4. In apparatus of the character described, a tube bundle including tubes and boxes connected to the ends thereof, means cooperating with the bundle to hold the tubes in an initially upwardly bowed condition and providing for bowing of the tubes in excess thereof, a shell encompassing the tubes, end covers for the shell, said end covers being vertically stifi, and horizontal ribs or webs supported by the end covers and abutting said boxes to resist relative separating movement thereof incident to tube expansion.

5. In apparatus of the character described, a bundle of tubes, boxes connected to the ends of the tubes, horizontal upper and lower beams 'joining the boxes, spacing means supported by said beams for holding the tubes in an initially bowed condition and providing for further bowing thereof, a shell, and end covers for the shell having abutting relation with respect to the boxes to resist relative separating movement of the latter incident to tube expansion.

6. The combination as claimed in claim 5 wherein the upper beams are connected to a first box and are slidable with respect to a second box and wherein the lower beams: are connected to the second box and are slidable with respect to the first to facilitate assembly of the apparatus.

7. The combination as claimed in claim 5 wherein the spacing means embodies one or more vertical plates having openings for the tubes and the beams with the beamopenings elongated vertically to permit of free upward bowing of the tubes.

8. In apparatus of the character described, a bundle of tubes, boxes connected to the ends of the tubes, means for holding the tubes inan initially upwardly bowed condition and providing for further bowing thereof, a shell encompassing the tubes, end covers for the shell, said end covers having vertical ribs to provide vertical stifiness, and horizontal upper and lower webs or ribs supported interiorly of each end cover and engaging upper and lower portions of said boxes to resist relative separating movement of the latter incident to tube expansion, whereby the tubes bow to accommodate expansion.

9. In apparatus of the character described, a pair of tube bundles disposed in tandem, boxes connected to the ends of the tubes of each bundle and adjacent boxes abutting, a shell encompassing the bundles, and end covers for the shell disposed in abutting relation with respect to the outermost boxes to resist relative separating movement of said boxes incident to tube expansion. V

JOHN A. POTTER. 

